CMU Dietrich school major declaration

How does the process work for major declaration to the Dietrich school in CMU ?
Should I announce a major in the application process (is there a place where I would declare, including the option to go undeclared) or do all students get accepted undeclared ?
or is it showing “soft” interest in a particular department within Dietrich without a hard declaration in the application.

Thanks

The Major I am interested in Dietrich is not IS, which I understand has a separate process.

thanks

https://www.cmu.edu/dietrich/advisory-center/faq/index.html

“ When does a student declare a major/minor?

First year students can declare their major at any time during the second semester of their first year. Students must declare before March of their sophomore year”

You are accepted into the College - any statement of intended major is informational only. Final declaration is as noted above.